[Qemu-devel] Re: [PATCH] Fix up pxe boot

[Avi Kivity <avi@qumranet.com>]

Glauber Costa wrote:
> On Sun, Sep 07, 2008 at 09:42:07AM +0300, Avi Kivity wrote:
>   
>> Glauber Costa wrote:
>>     
>>> After a second look, here's what it seems to me:
>>>
>>> It's not in a generic place, such as ldl, because in general, we may want to grab
>>> a 32-bit value from a 64-bit address. This is perfectly valid.
>>>
>>> It's a specifity that the pop instruction, when not in long mode (manual says that in 64-bit mode
>>> no 32-bit operand is valid, but then again, qemu should use the POPQ macro), that ssp:sp may overflow,
>>> but we don't want it.
>>>
>>> It would be possible to do something more generic if we had a segment_to_linear() function, that returned
>>> the linear address, but we don't.
>>>
>>> Does it make more sense to you?
>>>   
>>>       
>> Yes.
>>
>> I guess tcg code is mostly safe since it generates 32-bit additions for  
>> segment bases, so this is limited to the places you identified.  And a  
>> helper to add segment bases would be helpful.
>>
>> -- 
>> error compiling committee.c: too many arguments to function
>>
>>     
>
> what do you think of the attached version?
>   

Looks fine to me.  One can thing of a cleverer helper (that receives the 
segment number and adds its base to the offset), but there's not reason 
to do this all at one.

-- 
error compiling committee.c: too many arguments to function